panfrost: Use correct NO_DITHER field on MFBD

Signed-off-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>
diff --git a/src/gallium/drivers/panfrost/pan_context.c b/src/gallium/drivers/panfrost/pan_context.c
index 26276cd..c022e95 100644
--- a/src/gallium/drivers/panfrost/pan_context.c
+++ b/src/gallium/drivers/panfrost/pan_context.c
@@ -1225,6 +1225,9 @@
                                 if (is_srgb)
                                         rts[i].flags |= MALI_BLEND_SRGB;
 
+                                if (!ctx->blend->base.dither)
+                                        rts[i].flags |= MALI_BLEND_NO_DITHER;
+
                                 /* TODO: sRGB in blend shaders is currently
                                  * unimplemented. Contact me (Alyssa) if you're
                                  * interested in working on this. We have